Arduino

It’s been a while since posting about the InMoov robot hand I started building last year. Previously I had everything assembled and was using some direct controls in Grasshopper (plugin for Rhino) to test and tweak the movements of the fingers and wrist (click here to see the last video). That was fun, but not as fun as being able to control the fingers wirelessly from across the room!

Using MIT App Inventor, I’ve created a very basic mobile app that now allows the fingers and wrist to be controlled on my phone using a Bluetooth connection to the Arduino board. It’s nothing fancy right now, just some simple sliders that control the servos, but now that the basics are working some more automated movements could be set up eg. by using the built-in sensors of the phone, movements could be controlled by simply tilting the phone.

In order to display the working InMoov hand at the CreateWorld Conference last year, I also built a display box from plywood since the arm is not really attached to anything and there are a lot of electronics dangling around that are a bit too messy for display. It actually makes moving the hand around and working on it quite a bit easier now since it’s raised up as well. If I had files for this case I would share them, but I went old-school for this one and just created it freehand with a jigsaw – I’m not completely reliant on digital manufacturing (yet!). Inside the box on the right are all the messy electronics, and a hole for the Arduino USB cable to reach through to connect to computer when needed.

I’ve also 3D printed a stamp with my name and the edditive logo to “tag” this project. Using 3D printing to make custom stamps is something I wrote about in one of my first ever blog posts, click here to take a trip back in time. It’s always the little details that bring a project to life for me.

Yes finally the InMoov robot arm I’ve been slowly printing and assembling is complete and functioning with only the occasional little hiccup. I thought I was really close in my last post where I had assembled all the 3D prints and electronics, but it is definitely the last 10% that takes the most work.

Tensioning the braided lines just right and tying them to the servo’s is a painstaking task, especially in the heatwave we’ve been having in Australia, where you’re trying to resist the urge to wipe sweat from your face while you tie the knot just right… I felt a bit like a surgeon out in a humid jungle performing emergency surgery. A few little broken bits along the way as well from prints splitting or glue not holding, so it’s a relief to finally iron out all the kinks and start playing with the controls.

As you’ll see in the video, I’m using Grasshopper (plugin for Rhino) with the addition of Firefly to control the hand movements at the moment – if you’ve followed my blog for a while you’ve seen multiple demo’s of this software and why I think it’s so good, so I won’t bore you here (if you’re interested check out my project which was displayed at Design Philadelphia 2015). But it basically means I can manually adjust the servo’s in real-time using a simple slider for each finger, or connect fingers to the one slider to control them all at once and create a fist for example. It really makes those final tweaks to the servos easy.

I hope you enjoy seeing this arm come to life – it’s quite inspiring when you see it in real life, especially if you’re familiar with 3D printing and the time it takes just to print all of these parts. Now I can finally start modifying this project and experimenting with the controls, the build is only just the beginning for this robot.

– Posted by James Novak

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The 6 servo’s needed to build the InMoov robotic arm/hand arrived since my previous InMoov post, and are now installed and working individually. All up they cost about $35AUD on Ebay. The Meshmixer hack for the stands I discussed in the last post also worked quite well, and luckily no other stands to mount the servo’s have needed re-printing – just a few spots of super glue to prevent any minor splitting between the printed layers. This means that most of the assembly of the arm and wrist is now complete, other than running all the lines to control the fingers (a big job I’m not looking forward to). Below is a video of the wrist movement using a MG 996 servo – sounds like it means business!

Nothing particularly exciting just yet, although it’s nice to see the InMoov showing the first signs of life (Frankenstein anyone?). As you can see I’ve connected this servo to an Arduino Uno, and am manually controlling the movements using Grasshopper and Firefly, both plugins for Rhino 3D CAD software. I’m not sure if any other InMoov makers have done this, but if you’ve followed my blog for a while you’ve probably seen previous demonstrations of how you can use what is essentially a 3D CAD program to control the Arduino in real-time, something I’m very excited about. I certainly aim to continue using this visual programming language (VPL) to interact with the arm, perhaps making it more intuitive and interactive to control. Next step: 3D printing the fingers.

– Posted by James Novak

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3D scanning has featured a few times on my blog (eg. see my custom virtual reality headset which perfectly fits my face), so it was only a matter of time until I bought a scanner for myself. Earlier in the year Kickstarter convinced me to help fund the Ciclop 3D Scanner from Cowtech, a $99 open-source system that was impossible to refuse. Yep, $99!

Well here it is, built over a couple of days and making me feel like a kid again with a new kit of Lego. I bought the cheapest version of the scanner, choosing to 3D print the components myself (naturally!) which can be freely downloaded from Thingiverse. These worked really well, only a few areas where support material was time-consuming to remove, and were all done on the small build plate of the UP Plus 2. The top left photo shows most of these 3D printed parts (12 in total needed).

After receiving the other scanner hardware from Cowtech this week, it was finally time to put this kit together – no simple task after I snapped one of the key parts early in the assembly process! You can see the 2 broken pieces of acrylic to the left, which are both from the long arm connecting the 2 main octagonally-shaped hubs in the middle photo at the top of the page. So far Araldite seems to be holding them, and this snapping seems to be a common problem people are reporting – maybe a bit better tolerances required in the laser cut pieces, or a different material that’s not quite so brittle.

Otherwise the assembly process has been quite straight forward, the video provided by Cowtech is very easy to follow, especially if you’re a little familiar with Arduino’s. There are some really clever details in the way nuts slot into the laser cut pieces and screws slide through the 3D prints that I’ve never seen before, so as a designer it was fun to discover these details. I really appreciate the tolerances for many of the different parts fitting together, from laser cut to 3D print to machined screws, I am honestly surprised how well they all came together for me. So in the top right image you can see the final result – I have to admit I feel like an extra 3D printed part is required to cap off the top above the camera, it doesn’t look right to me so this might be something I make myself soon.

The challenge I’m having now is that I can’t get my camera to be recognised by the recommended open-source software for the scanner, Horus. I’ve spent hours installing software and drivers, rebooting my computer, uninstalling, installing in a different order, rebooting… Nothing is working. Hmmm, a bit frustrating but as I’ve learned with these sorts of new products from Kickstarter, sometimes it can take some time for people to start posting solutions and updates as my order was dispatched quite early and there is just not much up on the forum yet. Hopefully soon!

Keep an eye out on my blog for updates, and hopefully soon some successful 3D scans!

– Posted by James Novak

Update 7/8/2016:

After some ideas from the Cowtech Facebook Group, I have solved the connectivity problem – hopefully it helps anyone else that reads this. Firstly the Cowtech Scanning Guide says to plug in the camera to set it up in Horus – but you actually need to plug in the entire scanner – 2 USB’s and power. I then went into the preferences, selected the appropriate camera and serial, then changed the Arduino type to “Arduino Uno” and clicked “Upload Firmware” (shown left). I had to close and then re-open Horus, but now it’s all up and running. Hopefully the rest of the calibration goes a little smoother. I think the instruction booklet from Cowtech needs to make this clearer, and include these preference changes.

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OK so some people might look at this and think it’s just a box, but when you stop and think that 2 hours ago this “box” had never before existed in the entire span of human history, and that it was made on my desk, with a printer, well that’s pretty cool!

That might be over-dramatising things just a little, but there really is something very rewarding about 3D printing a custom enclosure to contain your electronics. I have quite the collection now, for example an Arduino enclosure and a Wiiduino. In this particular case a custom PCB has been manufactured, and we need to contain it in something for trials, keeping all the wires and mess tidy and giving the appearance of a real wearable product as it one day could be.

The PCB is about the size of an Arduino Uno, with a lithium battery that needs to be housed inside as well. I started by modelling the PCB in Solidworks, just as I have done in previous projects. While many people would only bother creating a simple block model of the overall dimensions, I’ve gone to the trouble of accurately modelling all of the key components like LED’s, buttons and connectors as shown above. This means that in the enclosure design, I’ve been able to play with form, giving the design tapered edges to make it seem slimmer, and accurately place holes and details for the various components. In doing so, the first 3D prints fitted successfully, saving time stuffing around later. These were printed on my Cocoon Create, which is still going along nicely, thanks Aldi!

I’ve also opted to use 2 screws to secure the enclosure halves, as snap details on such small enclosures can be fiddly when using desktop 3D printers – if you don’t print them in the right orientation, they just snap off. With holes already placed on the PCB, it makes sense to use these to both secure the 2 shells, and hold the PCB in place. So you get the full picture, here’s the 3D model for you to spin around.

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Most of the time when you’re playing around with electronics, or sharing them with people, you want the circuits and parts to be as clear as possible for viewers to understand or modify. However occasionally you may have the realisation that what you’ve got is a little bit special, or at the very least you don’t want to be serving up your hard work on a silver platter for someone to copy without putting in some hard yards of their own. That’s where I’ve found 3D printing to be an excellent tool – creating a simple enclosure that neatly hides away the circuitry inside a box of mystery!

I’ve previously done this for the Wiiduino, providing a clean object suitable for exhibition at Design Philadelphia, but this time my purpose was as much about hiding away the electronics as it was about providing a neat, compact electronics module to show at the Wearable Tech in Sport Summit in Melbourne. In the above images you can see the raw electronics (I don’t mind if you see them 😉 ) and the 3D printed enclosure I quickly designed in Solidworks and 3D printed on my Cocoon Create 3D printer the evening before the conference. Ahh yes, the beauty of having a 3D printer at home to quickly create almost anything!

If you look closely at the enclosure you will notice some imperfections – the main lower part lifted in the corners and caused some separation of layers, while the lid obviously has some shifting layers, probably because of the orientation and speed I printed them. Honestly I’m just happy they printed out and were usable with no time to muck around at the last minute! Just like the Wiiduino enclosure, a little bit of paint brought out the logo and makes the enclosure pop as something much more resolved and purposeful (as opposed to an anonymous blank box).

If you’re not as confident with CAD and accurately measuring your circuitry, there are some great free models that will fit Arduino’s and Raspberry Pi’s which you can download from Pinshape or Thingiverse. They make a great starting point, and you can always add your own logo or details following my Pinshape tutorial on using Meshmixer to modify a .stl file.

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Yes it’s as simple as the title says; I can now control the movements of my useless Solidoodle Press (and probably almost any other 3D printer) using a Wii Nunchuk!

Don’t ask me why. It’s more of a personal challenge to see if it could be done, and now that it can, I have a few fun ideas for this. The whole thing was surprisingly simple, and builds upon some previous work where I used Wii Nunchuk’s to customise a 3D CAD model, and of course my work using Rhino CAD software combined with the Grasshopper and Firefly plug-ins. In simple terms, I’ve managed to convert the X and Y signals from the Wii Nunchuk’s joystick into the X and Y G-code commands used by most 3D printers. It’s a little clunky, but at the same time it’s pretty cool to directly control this machine.

With a couple of buttons on the front of the Wii Nunchuk it won’t be hard to add some extra functionality to this, although my intention is certainly not to try printing plastic using this controller, there’s just no real reason to. You will just have to check back in later to see where this experiment goes!

– Posted by James Novak

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Last year I posted a bit of an inside look at a small project I was working on for my PhD (click here to have a look back at the post) but couldn’t say much since it was for an upcoming conference. Well that conference has been and gone, and my full paper has just been published online for you to read.

In essence it was an exploration of something called interactive fabrication, whereby someone with no CAD or design experience can actually create their own unique 3D printed pen using the ‘testing pen’ shown in the top right image. As you grip this pen, sensors translate the force of your grip in real time into a 3D model that is ergonomically correct for you. You then draw a closed shape such as a hexagon on a piece of paper, hold this up to your computer’s webcam, and this shape is automatically translated up the shaft of the pen. It’s as simple (and behind the scenes very complex) as that! The top left photo shows 4 different pens from 4 different people used during the testing of this project.

The complete process is controlled within Rhino 3D, using the Grasshopper plugin with Firefly to communicate with an Arduino, which I’ve explored in previous projects. There are plenty of improvements that can be made to this design, but as a prototype it certainly proves the potential to embed sensors within a product and automatically create custom functional products for people without the need for them to learn complex CAD software. As it happens, this is a large focus of my PhD!

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I just wanted to quickly post a video showing some of the great projects to come out of a class I taught this semester at Griffith University called Human Machine Interfaces. These particular projects are presentations after 6 weeks of development combining research, design and prototyping into this short time-frame. I was super impressed to see things like exo-skeletons and products bringing gamification to life, of course combined with 3D printing, Arduino’s, Rhino CAD with Grasshopper and Firefly, and of course anything else the students could get their hands on.

Watch out designers, these guys will be changing the world! Some of these students will also be exhibiting these projects at the upcoming 3D Printing Forum in Brisbane on November 24 (click here to read my post), so come and say hello 🙂

– Posted by James Novak

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Normally I never use this blog to promote anything, but with a 2-day 3D printing forum happening in my part of the world in November, I think it’s my duty to put it out there! Normally I have to travel around the world to attend events like RAPID, so it’s great that my university has sponsored one right here in Brisbane, Australia.

If you’re in this part of the world, or can get here, click this link to read the full schedule and register to attend. I will also be showing my latest wearable technology PhD project (you may notice some of my previous work featured in the flyer!), alongside a selection of students from my Human Machine Interfaces class who have spent the semester using Arduino’s and 3D printing to create everything from exo-skeleton hands to wearable posture correction devices.

Key speakers include Dr Lionel Dean from Future Factories who I’m really interested to speak to about his work in computational design, and Professor Olaf Diegel whose 3D printed guitar you are probably familiar with. Should be a great event so I hope to see you there!